Monday, May 5, 2008

Vision Care: Preventing Glaucoma

Although we make take it for granted, few things are more precious to us than our sight. Imagine, then, that one day you realize you can’t see objects out of the corner of your eye. You may chalk it up to eye strain or aging, but then -- suddenly -- you find you have no side vision at all; it’s as if you’re looking through a tunnel. Over time, if you don’t seek treatment, even this narrowed vision will disappear into blindness.

What is glaucoma?
Glaucoma, a progressive eye disease that damages the optic nerve, has resulted in blindness for an estimated 120,000 Americans. It’s been called the “silent thief” because most people with undiagnosed glaucoma have no symptoms until they begin to notice they’re losing their peripheral vision. By that time, the optic nerve is already damaged. And once gone, areas of lost vision cannot be restored.

Your eyes maintain their shape due to inside (intra-ocular) pressure. Glaucoma causes this intra-ocular pressure (IOP) to increase above values considered normal. (Normal IOP is different for every individual.) Over time, increased IOP compresses the nerve at the back of the eye, resulting in a slow loss of vision (“open-angle glaucoma”) without noticeable symptoms. The more severe form, known as “closed-angle glaucoma,” has extreme symptoms -- sudden eye pain, nausea, headache, and rapid vision loss -- and is an ocular emergency. Permanent loss of vision may occur in as few as three days.

Ninety percent of glaucoma cases, however, are open-angle glaucoma -- the less severe and more easily treated form of the disease. Although anyone can get glaucoma, some people are at higher risk than others. They include:
  • Anyone over age 60 (or those older than 45 who have not had regular eye examinations)
  • People with a family history of glaucoma
  • Afro-Americans over age 40
  • Diabetics
  • People with severe myopia (near-sightedness)
What can be done about glaucoma?
Studies have shown that early detection and treatment of glaucoma -- before it causes major vision loss -- is the best way to control it. See your eye-care professional at least every two years (more often if you are high-risk) for a complete eye exam, including IOP checks. IOP checks are simple, quick and painless procedures that measure the fluid pressure inside your eyes. They include a “puff test,” which measures the resistance of your eye to a puff of air blown against its surface; and use of a tonometer, an instrument that is lightly touched to the surface of your eye for a more accurate measurement. (Don’t worry -- prior to this test, the surface of your eye is numbed with eye drops, and the procedure itself takes just a moment.)

Additional tests may also be performed. You may be given a visual field test, which measures your side (peripheral) vision and can detect even minute losses of vision. For this test you will be asked to focus your eyes straight ahead at a central point, and then to say when you see a spot of light appear at the side. Your eye care professional may also check for signs of optic nerve damage by placing drops in your eyes to dilate (widen) your pupils so he can get a better view of the optic nerve.

Treatment of glaucoma depends on the type and severity of the disease. Closed-angle glaucoma usually requires laser treatment to make a new opening in the iris, along with medication to help clear the angle. Conventional surgery is sometimes necessary if laser surgery is unsuccessful. The more common open-angle glaucoma treatment usually begins with prescription eye drops or oral medication to lower intra-ocular pressure. Complementary treatments for glaucoma may also be suggested, and although these should not be used in place of your prescribed treatment, they may help control the disease. Vitamin B12, for example, has been shown to help prevent loss of field vision, and vitamin C may lower intra-ocular pressure. Vitamin E is helpful in removing particles from the lens of the eye, and can aid in the protection of the tissue of the eye. Important minerals for eye health are zinc, selenium and magnesium.

Of course, the ideal way to ensure you get an adequate supply of these essential vitamins and minerals is to eat a balanced diet, but if you’re like most Americans, you don’t always eat as you should, so take a nutritional supplement. Certain lifestyle changes will also help. Studies indicate a brisk daily walking program may reduce intra-ocular pressure as much as pressure-reducing eye drops. And regular exercise not only helps reduce eye pressure on its own, it can have a positive impact on glaucoma risk factors such as diabetes.

Right now, there is no way to prevent glaucoma, nor is there a definite cause of the disease. It’s a lifelong illness, but proper treatment can prevent loss of vision. Get regular eye exams as part of a vision care plan to safeguard your precious sight. And if you have symptoms of diabetes, make sure to let your eye doctor know. He may want to check your eyes more frequently.

For the latest glaucoma vision care recommendations, visit the Glaucoma Research Foundation.

NOTE: The information in this article is not meant to take the place of professional medical advice. Check with your doctor before making decisions on any vision care supplement.

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